Filed from 6 published puzzles

NITRIC

Set to 2 different clues across 6 published puzzles, most often “Kind of acid” — The New York Times, Tuesday, 19 July 2011.

6 letters

Every clue on record, most used first

  • Kind of acid5 times

    The New York Times — Tuesday, 19 July 2011

  • ___ acidonce

    The New York Times — Friday, 27 February 2004